Automatic brake.



No. 633,185.` Patented Nav. 2s, |899.

A. E. Nonms.

AUTOMATIC BRAKE.

(Application led July 13, 1899.)

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llNiTnn STATES PATENT @rrr-Cnt ALMON E. NORRIS, OF CAMBRIDGE, MASSACHUSETTS.

AUTQMATIC BRAKE.

srnciiercA'rioN refining part of Lettere Patent No. 638,185, dated November as, ieee'. Appiieeuen ned July is, 189e. serial No. 723,659. (No model.)

T0 'mZ-Z whom it may concern.-

Be it known that I, ALMoN E. NoRRIs, of Cambridge, county of Middlesex, and State of Massachusetts, have invented an Improvement in Automatic Brakes, of which the following description, in connection with the accompanying drawings, is a specification, like letters and iigures on the drawings representing like parts.

This invention relates to a brake capable of use in many different connections, but of peculiar importance in connection with a hoisting apparatus, in combination with which it is herein illustrated and described.

In hoisting a load or buckets of material through the agency of a drum or otherwise the suspendedl load or buckets,\vhich are connected with the cable usually wound around the drum, by reason of their weight fall as soon as the power from the hoisting engine or motor is shut off. With my improved brake, however, the load cannot drop when the power is stopped, for the moment that the load begins to drop the brake is immediately and automatically set, and thereby arrests further descent of said load.

In the drawings, Figure l is a side elevation of a motor for operating the hoisting apparatus and is shown provided with a brake mechanism constructed in accordance with my invention. brake-operating appliance, and Fig. 3 is a top plan view of the same.

In the embodiment of the apparatus herein illustrated I combine with a rotative object a friction-brake which ordinarily surrounds the circumference of the rotative object, and the construct-ion is such that the rotative object may freely advance or rotate forwardly, but a very slight backward rotation of said object sets the brake automatically, so as to limit the further backward movement of the object controlled thereby, and consequently prevent the fall of the bucket or other load suspended from the drum.

In the representation of the brake illustrated in the accompanying drawings it includes in its construction a strap or band of suitable material which acts against the pe- Fig. 2 is a front View of the.

riphery of a disk or wheel constitutingapart of the hoisting apparatus, and the inner face of the band or strap is provided with a series of wear-blocks,ordinarily made of wood,which directly engage the periphery of the wheel. In the drawings, 2 indicates a power-shaft, and 3 a disk or wheel which normally rotates in the direction of the arrow, Fig. l, and the pitman or connecting rod 4 is jointed to the crank-pin 5 upon the wheel 3 and is connected with a suitable motor, thereby to operate the wheel. TheA shaft 2 also carries a drum 6, which runs loose on said shaft and which is clutched frictionally or otherwise thereto when it is desired to elevate a load, such as the bucket 7. The bucket 7 is connected to the cable or rope S, and the opposite end of said cable is wound around the drum. If for any reason the propelling power should be removed, the bucket if in mid-air under ordinary circumstances would fall, but such a contingency as this is not possible in the present case, as the instant the disk 3 is reversely rotatedl the automatic brake will be set in action to arrest further reverse rotation of said disk, and consequently the further fall of the bucket connected thereto, it being understood that an almost imperceptible backward movement of the bucket is necessary to effect the action of the brake through the intervention of an automatic actuator, which may be of any suitable kind.

The actuator in the present case is shown as consisting of a rocker A, loosely mounted upon the shaft l0, which is xed to the bed- A plate l2 of the apparatus in adjacence to the periphery of the wheel 3.

The brake (denoted in a general way by B) is shown as including in its construction a band 13, having secured to its inner face the closely-arranged series of wear-blocks 14, which act directly against the wheel to stop the same.

The brake B is represented as consisting of two sections (denoted, respectively, by l5 and 16) provided with offsets or ears 17 and 18, having holes to receive the bolt 19, the opposite ends of which are threaded to receive adjusting and check nuts, and the bolt, with its nuts, 'serves as a convenient and simple means for drawing the two ends of the strapsections toward 'each other for the purpose of taking up any wear that may take place upon the acting faces of the wear-blocks 14:.

The lower ends of the two parts of the brake are connected to the upper and lower bolts or pivot-pins 2O and 2l upon the actuator A, and it will be seen upon an inspection of Fig. l that the bolts or pivotal points are located at different distances from the axis of oscillation of the actuator A, the point of attachment of the section 15 being very much nearer said axis than the point of attachment of the other strap-section 16.

As hereinbefore set forth, the forward or hoisting rotation of the disk is indicated by the arrow in Fig. l, and the outer surface or periphery of the wheel 3 by acting against the wear-blocks 14C will exert to the section 16 of the brake B a pull or stress, which is applied to the actuator or rocker A through the long radius thereof, and the tendency', therefore, is to loosen the band or strap, so as to permit the free or normal operation of the wheel, and thereby not affect the hoisting action of the apparatus. Should theloaded bucket '7, however, be suspended from the drum 6, when the power is shut off the bucket will fall, and may do so, and through the intermediate parts the wheel 3 will be reversely turned, and a pull will be exerted upon the actuator or rocker Athrough the short radius thereof, so that said actuator is swung to the dotted-line position shown in Fig. l, thereby multiplying the power to such an extent that the lower portion of the strap will be pulled for a relatively considerable distance, thereby tightening the brake upon the wheel and preventing any further backward movement of said wheel, and consequently the falling of the bucket, and it will be evident that the backward motion of the parts in the act of setting the brake is exceedingly slight.

The actuator A, which is loose upon the shaft, is shown as including in its construction two substantially similar plates or sections 30 and 3l, united by the curved web 32, partially surrounding said shaft and the upper end of which is adapted to engage the lower end of the strap-section l5, thereby to limit the ineffective motion of said actuator or in a direction opposite to that it takes in setting .the brake B.

To augment the automatic action of the wheel 3 in effecting the operation of the actuator A, and thereby the working operation of the brake, means of a suitable nature, such as the coiled torsional spring 35, will be employed.

The spring 35 surrounds the pin or shaft 10, and one end of it is secured to the two-part collar 36, that is clamped to the outer end of said shaft or pin and also to the actuator A.

Having described the invention, what I claim is- 1. A brake mechanism comprising a wheel, a band-brake surrounding said wheel, an oscillatory actuator, the ends of the band-brake being connected to said actuator at points 1ocated at different distances from its axis of oscillation, and the actuator being operated through the band-brake on the reverse or backward rotation of said wheel, thereby to set the brake, and automatically-operative means acting against said actuator to accel erate the motion thereof.

2. A brake mechanism comprising a wheel, a band-brake surrounding said wheel, and an oscillatory actuator, the ends of the bandbrake being connected to said actuator at points located at different distances from its axis of oscillation, the actuator being roperated through the band-brake on the reverse or backward rotation of said wheel, thereby to set said band-brake, and a spring located to act against said actuator to augment the efficiency thereof.

3. A brake mechanism comprising a wheel, a band surrounding said wheel, a fixed shaft, an actuator loosely mounted upon said shaft, a collar fixed to the shaft, and a coiled spring surrounding one end of the shaft and secured respectively to said collar and actuator.

4. A brake mechanism comprising a wheel, an actuator mounted for oscillation and consisting of two parts, a brake-band surrounding said wheel and secured between the two parts of the actuator at points'located at different distances from the axis of said actuator, and a web uniting the two parts of the actuator and adapted to engage the brakeband, thereby to limit the movement of the actuator in one direction.

5. A brake mechanism comprising a wheel,

Van actuator mounted for oscillation and consisting of ltwo parts, a brake-band sur-rounding said wheel and secu-red between the two parts of the actuator at points located at different distances from the axis of said actuator, a web uniting the two parts of the actuator and adapted to engage the brake-band thereby to limit the movement of the actuator in one direction, and a spring in position to bear against the actuator to augment ythe efficiency thereof.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALMON E. NORRIS.

Vitnesses:

HEATH SUTHERLAND, FREDERICK L. EMERY.

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